Question

The length of a potentiometer wire is . A cell of emf E is balanced at a length /3 from the positive end of the wire. If the length of the wire is increased by /2. At what distance will the same cell give a balance point?

• A. 2/3
• B. /2
• C. /6
• D. 4/3

Hint:

Balance length is inversely proportional to total wire length.

Answer 1

The Correct Option is C

Step 1: Potential gradient k 1/L.
Step 2: New length, L'=+()/(2)=(3)/(2)
Step 3: Balance length varies inversely with length, '=()/(3)×()/(L')=()/(6)